These studies evaluate the extent to which gender, ethnocultural and menstrual cycle differences in pain sensation and pain report are due to differences in neurosensory sensitivity, and the extent to which the differences are due: (1) to psychosocial and personal factors which influence report bias (stoicism or squeamishness), and (2) to the meanings associated with words used to describe sensory and emotional experiences (semantics). Sensory Decision Theory (SDT) and Multivariate Scaling (MVS) will be used to interpret the responses of young adult women and men of African American, Anglo American and Puerto Rican background: (1) to noxious and milder calibrated hot and cold physical stimuli, and (2) to sensory and emotional descriptors of pain and suffering. Studies will be conducted at five precisely defined menstrual phases in normally cycling women, time-matched to men. SDT will be used to explore the hypothesis that women's more "sensitive" traditional thresholds are largely, but not entirely, due to a response bias (B) to report more pain, rather than to differences in discrimination sensitivity, P(A). Both SDT measures are expected to vary during the menstrual cycle. To test the hypothesis that women have a more sensitive secondary pain (C-fiber) system, responses to brief stimuli will be obtained as parameters of heat (rise-time) and cold (adaptation level) are varied. MVS Individual Differences Scaling and cluster models will be used to investigate gender and ethnocultural differences in the configuration of sensory, emotional and other features (dimensions and clusters) of the pan and suffering space for both physical stimuli (heat) and verbal stimuli (descriptors). It is hypothesized that in the group stimulus space the distance between verbal and physical stimuli along the intensity dimension will be greater for women, especially at ovulation, and that women will find the emotional rather than the sensory dimension to be the more salient. Ratings of noxious heat and cold stimuli by descriptors defined by cluster analysis will uncover the different meanings that various sex/ethnocultural groups give to many of the descriptors.